Histological Studies Of The Vomeronasal Organ Of African Giant Rat (Cricetomys gambianus, Waterhouse)

The vomeronasal organ (VNO), a chemoreceptive organ was studied in African giant rat (Cricetomys gambianus, Waterhouse), a macrosmatic animal, by means of gross dissection and light microscopy. The VNO was located in the rostral part of the base of the nasal septum. It was tubular in shape, about 10.6 mm in length and opened in the rostral region of the nasal cavity, with a blind caudal end that terminated in glandular branches. Its lumen in the middle segment was lined by sensory epithelium on the medial wall and non-sensory epithelium on the lateral wall. The sensory epithelium showed sensory, supporting and basal cells, whereas the non-sensory wall contained psendostratified columnar cells with ciliated epithelium. Vomeronasal glands were present in the lateral wall and on the dorso-lateral region between the sensory and non-sensory epithela. Intraepithelial blood vessels were observed on the medial sensory epithelium. Nerve bundles were also apparent in the medial sensory wall. The vomeronasal capsule incompletely housed the organ and showed ossified areas. The histological observations suggest that the VNO isan important organ in sexual behaviours as in other rodents and will throw more light on future studies of the vomeronasal organ. Keywords: African giant rat, Histology, Chemoreception, Vomeronasal orga

Physiologic Evidences Of Good Tolerance Of Concurrent Rumen Fistulation And Duodenal Cannulation In West African Dwarf Sheep

Twelve adult West African Dwarf (WAD) sheep of mean age and body weight of 18 ± 1.19 months and 14.69 ± 256 kg body weight respectively were used to study the compatibility of concurrent rumen fisulation and duodenal cannulation with normal life. The compatibility with norma life was assessed by differences in body weight, voluntary feed intake, rectal temperature and some haematological and biochemical parameters for a period of eight weeks between test and contro groups. During the sudyperiod, all the six animals survived the surgery. There was no significant (p < 0.05) dfference in body weight between the test and control groups for the entire study period (week 1-8). The mean rectal temperature of the test group was significantly (p < 0.05) higher than the control group on week 1(44.6 ± 3.150C), week 2 (43.26 ± 414 0C) and week 3 (41.15 ± 6620C) after implantation. Packed cell volume (PCV) and erythrocyte count (EC) were significantly reduced in the test group within the frst three weeks (33.19 ± 141 to 24.45 ± 1.39%and 7.01 ± 134 to 437 ± 1.58 x 106μl) respectively. On the contrary, total leukocyte count (TLC), and neutrophils were significantly higher in the test group between weeks 1 to 3 (12.48 ± 435 and 31.09 ± 3.67 respectvely) compared to the control (8.06 ± 0.95 and 23.41 ± 2.09 respecvely. Lymphocytes were insignificantly higher in the test group while voluntary feed intake was insigniicantly reduced in the test group throughout the eight weeks. Biochemical analyses revealed that serum creatinine was signicantly higher in the test group at week 1 (3.62 ± 1.18) and week 2 (3.08 ± 1.44) afer surgery. There was however, no significant difference in serum total proteins during the study period. Serum potassium concentrations were sgniicantly decreased inthe test group at week 1 (4.96 ± 1.03 to 1.34 ± 0.04). Sodum was also signcanty reduced (146.08 ± 3.78 to 96.03 ± 6.21) but on week 3 post impantation (PI). On the other hand, serum globulin was significantly higher in the test group throughout the study period. Gross observationsof incision sites showed adhesions characterized by coalesced tissue granulations. The study has shown that the use of polymetric materials in fabricating rumen fistulae and duodenal cannuale could pave way for increased routine nutritional studies in ruminants particularly in developing countries where the availability of these materials constitute great limitationto research involving rumen studies. Keywords: Duodenal cannulation, Rumen fistulation, West African Dwarf shee

The role of main olfactory and vomeronasal systems in animal behaviour and reproduction

In many terrestrial tetrapod, olfactory sensory communication is mediated by two anatomically and functionally distinct sensory systems; the main olfactory system and vomeronasal system (accessory olfactory system). Recent anatomical studies of the central pathways of the olfactory and vomeronasal systems showed that these two systems converge on neurons in the telencephalon providing an evidence for functional interaction. The combined anatomical, molecular, physiological and behavioural studies have provided new insights into the involvement of these systems in pheromonal perception and their influence on the neuroendocrine pathways. The olfactory and vomeronasal systems have overlapping functions and both are involved in responses to both pheromones and chemical odorants. Several studies in insects, amphibians rodents and ungulates have established the importance of pheromones in the astonishing influence exerted by the male on the reproductive activity of the female. The great diversity of signals used in chemical communication indicates that this communication is not mediated exclusively by pheromones. A number of pheromonal responses are not dependent on the vomeronasal system, but on the main olfactory system. The dual olfactory systems also have overlappng functons. The importance of this organ in reproductve and socia behaviours was the aim of carrying out the review on its basic morphology and functional correlations in order to encourage more future studies of this important organ of our local species and breeds of mammals.Keywords: Main olfactory system, Vomeronasal system, Pheromones, Behaviour, Mammal

Histologic and ultrastructural observations on the thyroid gland of the White Fulani (Zebu) cattle in Northern Nigeria

The histology and ultrastructure of thyroid gland of White Fulani (Zebu) cattle were examined during the postnatal developmental period to show if variations in morphology exist with age and in relation to tropical climate. Eight prepubertal and ten pubertal cattle of abattoir origin were used to carry out this study. Histologically, the thyroid consisted of well-developed capsule, interlobular connective tissue, follicular and parafollicular cells from prepubertal to pubertal age of 5 to 7 years. The follicular cells were cuboidal in prepubertal period with some variations, became predominantly columnar in pubertal age of 2 to 4 years and highly flattened cells were common in the older pubertal animals of  5 to 7 years. The colloid was observed in the lumen at all age and was PAS-positive with abundant peripheral vacuoles in the pubertal age of 2 to 4 years. Significant variations (p˂0.05) in structure of the thyroids were observed at all age and the follicular size and number of follicles increased as the cattle matured. Follicular height was reduced significantly in the older pubertal cattle of 5 to 7 years. Ultrastructurally, the follicular cells showed highly dilated cisternae of rough endoplasmic reticulum which decreased with age. Flattened follicular cells seen in the older pubertal cattle contained few cytoplasmic organelles and microvilli. Apically placed pseudopods and blebs were commonly observed in the pubertal age of 2 to 4 years. Lysosomal bodies increased with age of development. The parafollicular cells were encountered frequently in the prepubertal age than in the older cattle. They consisted of numerous dense secretory granules which increased in number with age. The present results suggest an optimum thyroid function during the pubertal. Our findings would be useful in interpreting changes in thyroid morphology during experimental and pathological conditions. Key words:  Cattle, postnatal thyroid, histology, ultrastructure

Toxicity and phytochemical constituents of aqueous extract of Ocimum gratissimum leaf

No Abstract.Nigerian Veterinary Journal Vol. 29 (3) 2008: pp. 48-5

Phytochemical characteristics of the root bark of Erythrina senegalensis

Phytochemical analyses were carried out on crude aqueous and ethanol extracts of the root bark of Erythrina senegalensis (RES) to validate its efficacy as a local herb for the treatment of filarial eye lesions. Thin layer chromatograph (TLC), using the solvent system chloroform and methanol (2:1) was done on aqueous and ethanol extracts of the root bark, with 3 mg Ivermectin, a commercial anti-filarial, anthelminthic and ecto-parasitic drug presented as Mectizan ® serving as standard. The analysis indicated the presence of alkaloids, proteins, flavonoids, saponins, tannins and carbohydrates in the root back extract. The relative fraction (Rf) value of Mectizan ® in ethanol extract was 0.942, while that of RES sample was 0.941. The Rf value of Mectizan ® in aqueous extract on the other hand was 0.954, while that of RES sample was 0.952. These results indicate that the root bark of Erythrina senegalensis may possess some anti-filarial as well as anthelminthic and ecto-parasitic activities. International Journal of Natural and Applied Sciences Vol. 2(1) 2006: 12-1

Anthelminthic efficacy of aqueous extracts of Garcina kola seed and stem bark against strongylid nematodes of small ruminants in Nigeria

The anthelminthic efficacy of the crude aqueous extracts of the seed and stem of Garcina kola against strongylid nematodes of small ruminants was investigated using the invitro egg hatch assay method. Compared to the water (control0 cultures, the extracts demonstrated significant (